Conditioning shampoos comprising various combinations of detersive surfactant and hair conditioning agents are known. These shampoo products typically comprise an anionic detersive surfactant in combination with a conditioning agent such as silicone, hydrocarbon oil, fatty esters, or combinations thereof. These shampoos have become more popular among consumers as a means of conveniently obtaining hair conditioning and hair cleansing performance all from a single hair care product.
Many conditioning shampoos, however, do not provide sufficient deposition of conditioning agents onto hair during the shampooing process. Without such deposition, large proportions of conditioning agent are rinsed away during the shampooing process and therefore provide little or no conditioning benefit. Without sufficient deposition of the conditioning agent on the hair, relatively high levels of conditioning agents may be needed in the shampoo composition to provide adequate hair conditioning performance. Such high levels of a conditioning agent, however, can increase raw material costs, reduce lathering, and present product stability concerns.
Obtaining good deposition of a conditioning agent onto hair is further complicated by the action of detersive surfactants in the shampoo. Detersive surfactants are designed to carry away or remove, oil, grease, dirt, and particulate matter from the hair and scalp. In doing so, the detersive surfactants can also interfere with deposition of the conditioning agent, and carry away both deposited and non deposited conditioning agent during rinsing. This further reduces deposition of the conditioning agent onto the hair after rinsing, thus further reducing hair conditioning performance.
One known method for improving deposition of a hair conditioning agent onto hair involves the use of certain cationic deposition polymers. These polymers may be synthetic, but are most typically natural cellulosic or guar polymers that have been modified with cationic substituents. The cationic charge density of such polymers, especially when used in a shampoo composition, is minimized so as to avoid incompatibility with anionic materials in the shampoo such as anionic surfactant. As such, most shampoos which contain both an anionic detersive surfactant and a cationic deposition polymer will maintain relatively low cationic charge density values for the deposition polymer in order to maintain physical stability of the shampoo composition.
A need still exists for improved conditioning performance in shampoo compositions.